Flash-light railway signaling system



Feb. 28, 1928.

A HOMIE Ys.

Feb. 2s., 192s.

1,660,332 R. J. HEWETT FLASH LIGHT RAILWAY SIGNALING SYSTEM I'lllll Fig. 3

IN VENTO/f.

v ATT RNEYS.

Patented Feb. 28, 1928.

yROBERT J. HEWETI; OF WESTFIELI), y'lhlilllf JERSEY.

.FLAsi-r-LIGHT ,RAILWAY SIGNALING SYSTEM.

Application led April 24, 1924. VSerial No. 708,687.'

`This invention relates to railway signaling systems in which lightsignals `are used for controlling train movements both `day and night in place of tlie'usual semaphore signal. The prese-nt ksignaling practice requires that the signal system should be capable of giving three indications for governing the movement of trains. u In the colorjlight signal systems as nowfpracticed,'these three indications,arevgiven'by the colors red, yelvlow and green. y

invention has for an object to provide an improved color light signal systeml in which two color lights, such as red and green, F for example, will give the three indications,

and which kwill bevrelatively simple andre- ,liable .Various other objects will be' apparent from the following descriptionof embodiments ofthe invention andthe novel features will be particularly pointed out hereinafter infclaims.

'ln accordance withthe invention, one of the lights, such as the yellowliglit, may be omittedA and in place of it a flashing condi- 7 tion of either or both of theY other lights, suchy as the greenlight or. the red light, may be substituted. For example, the -flashing condition of the green light or alternately both green land red lights may indicatevcaution and the steady condition ofthe]- green light indicate proceed; the steadycondition of the red lightindicates stop as usual. `In va similar way the flashing condition of the red light may be used for caution and the steady condition of the red light will indicate `stop and the steady condition of the green light will indicate proceed. The essential feature of the invention` consists -in the use of a steady condition and afilashing condition of the samelight for governing train movements. The system may therefore be termed a flashlight railway signaling system. y n f In the accompanying drawings Fig. 1 is aA circuit diagram illustrating the amilication ofthe invention to a stretch of track, with the color signal normally yused toindicate a clear condition of the track, `flashing to indicate caution;

Fig. 2 is a similar diagram, but illustratini;I another embodiment of the inventionin FCI which the danger signal flashes to indicate caution; and n l f Fig. 3 is a similar diagram but illustrating another embodiment of thejinvention in which'the clearand danger signals Hash alternatelyto indicate caution. y n

In 1 I have illustrated the complete circuit arrangement for controlling east bound flash light signal 102.jThe lower lightR is the usual red light signal. The

yellow light signal is not used.. The upper light G is the green lightsignal and is -providedwitli two operative conditions, .the

usual. steady greenlight condition which indicates proceed, and a yflashing green light conditionv which indicates caution.

flasher relay F 102 which will be described farther on.

The control circuits for signal 102 areas usual for thel control of light signals and are as follows: `Track section T 102 is provided with a track relavR-102 at signal 102 vand a track'ibattery TB 102 at the other end, that is at signal 106. The battery circuit for track battery TB 102`includes a special low resistance track relay A 102 rwhich ,is connected'in series relation withtrack battery TB 102 and is normally de-energized 'but will beenergized by thepresence of a train in track section T 102. zThepuipose of tlie'low resistancetrack relay A 102 will be shown further on.

f The line circuit for signal 102 is asyfollows z-fronineutra-l polar line relay L l102, Wire`1,contact 2 of Vtrack relay 'R 102, line wire 3, front contact l of yline relay L 106 The` flashing operative condition of the green light G may be produced by the polarized held energized in the normal magnetic condition, thus holding its polarized armature (not shown) and itspolar contact-fingers 2,6

and` 35 in. their normal or righthandposition as shown. The normal position of the polar ycontacts 26 and: 35 is now in a position ready to give the proceed indication on green signal G at signal 102.

W'hen rthere isa train in track section AvT o 106, track relay R v106 will'be de-energized andV thus'bykop'ening its contact12 will open the line circuit for line relay L 106, which i the terminals of battery MB 106 in relation Y to the line wire 3 and the common wire C, with the result that a negative current, i. e., a current of reverse direction, will pass battery M B 106 to line wire 3 and to line relay VL 102 at signal 102. The magnetic condition of line relay L 102 will` be reversed :and its polar armature` (not shown) will be thrown `to the opposite position and its polar contact fingers 26 and 35 to the left or reverse position, which closes its reverse polar contacts.V

37 and 36. The latterare now in aiposition for givin@ the cautionar i indication on creen n n b light signal G at signal 102.

` The energized and cle-energized conditions of line relay. L 106 at signal 106 and its `front contacts 9 and 4 and back contacts 11 Aand 10 provide the actions of a pole changer place of the usual pole changer mechanism Cri Vof a semaphore signal.

`The polarized flasher relay F 102 will now be described. Polarized relays inherently lrequire reverse currents for their operation.

This reverse current is usually supplied by a pole changing device of some suitable form. In thc design and operation of the polarized flasher relay F 102 a simple selfacting arrangement is usedby ineans of which the polarized flasher relay supplies its own reverse operating currentsfroni a direct current source without the `aid of an external pole changing device, and will now be described in connection with the associated devices which control its operation in giving a green flashlight signal on green signal G at signal 102. The associated de-v vices are the polar contacts 26 and 35 of the polar-neutral line relay L 102 which have `been describedand also the low resistance track relay A 100 which gis usually termed `the approach lighting relay.

Assume that there is a tra-in in track section T 106-1-this should give a flashing caution signal on green signal G at signal 102. Track relay R 106 is cle-energized, also line relay L-106 is de-energized and its neutral armature (not shown) is down thus closing its pole changingback contacts 11 and 10, which will supply a negative or reverse cur rent from battery M B 106 to line wire 3 and to line relay L 102 at signal 102. The line relay L 102 will throw its polar contacts 2 6 and 35 to the left closing contacts 37 and 36. Everything is now in a conditionfou giving the flashing cautionsignal on green light G.

With a following train in track Vsection T 100, approach lighting relay A 100 will be energized and by closing its front con- .tact21 closes the operating circuit for polarized flasher relay F 102 as'follows froin battery M B 102, wire 6, wire 20, front con tact 21 of approach lighting relay A 100,' wire 22, wire 23, front` contact 24 of line relay L 102, wire 25, polar contacts 26H37, wire 38, wire 38a, right hand coil 39 of polarized flasher relay F 102, wire 40, wire- 44,. polar contact linger 45, contact 46, wire would result. l/Vire 44` and polar contact 45 diverts the currentfroni coil 42, and coil 39 only is effective, and this causes a magnetic flux to be set up in both core pieces and the yoke piece in such a direction as will throw the polar yarrnaturetnot shown) and its .polar Contact finger 45 to the right,

thus `closing contact 48 and shunting out coil 39 with coil 42 `only-in circuit. Coil 42 will now cause a magnetic flux to flow in the opposite direction in` the` core pieces and yoke, and this will throw the polar linger 45 to the left. These opposite actions will continue as long `as either contacts 21 24 or 37 remain closed.

`Briefly stated thedirect currentfroin battery M B 102 flowsalternately in opposite 'directions through coil `39 or 42 and this produces alternating magnetic Vflux conditions inthe core pieces and the yoke piece of the magnetic circuit. Polar contactfinger 31 willnow operate in unison with op* ica erating contact finger 45 and opens and` closes the flasher circuit to the green light G which .is as follows z-froni battery M B 102, wire 6, wire 20, Contact 21 of approach lighting relayf A 100, wire 22, wire 30,contact finger `31 (which may be termed the flasher' contact), wire 32,l front contact 33 ofl line relay L `102, wire 34, `polar contacts 35, 36,

`now closed, Wire28, greeii'lightG and wires 29, 29, 29b and 7 to battery M B 102. Green light G will therefore flash in `unison with flasher contact 31 as long as approach `lighting relay A is energized by an approaching east bound train.

The polarized flasher relay F 102 .is only brought into action for flashing the caution indication on green light Gr. Polar contact 3.7 of line relay L 102 provides the selective control for operating flasher relay F 102 at thejproper time, that is when a cant-ion iiidication is to be given.V

The slow releasing feature of the flasher its polar armatureV andtheoperating conlll! VrelayF 102 produces a' `slow movement of ating contact y'45 4also Will augment the slow releasing effect of copper slugs on the outer endsofthe core pieces. "This slow action of the flasher --relay gives a slow `flashing niay, howeverbe in its -riglithand position.

l" ll'hewpolar ainiature of a polarized relay Will always reinain in the last position in which it Was thrown.

rThe invention as so far described relates rto the flash light operation of the green light'G. All other actions of the circuits relate to the regular or steady light operation of the red and green lights which are as usual, and niay be explained briefly as follows: Assume that the circuits-are in their normal condition Withfno train in track section T 106, track relay R 106 and line-rechanger contacts 9 and 4 are closed, and the normal or positive current Will be supplied L Vfroni battery MB 106 to line Wire 3,.to

line relayrL 102Whic`h Will'hold its polar contacts 26, 27 in its closed position as show-n` `An eastbou-ndtrain in track scction T 100 will energize approach lighting' relay A100y which Will close its contact 21 and clear green signal Gin its steady-light condition, the-light circuit being as follows:

froni-battery'MB 102, Wire 6, .Wire 20, contact 21, Wire 22, Wire 23, contact 24 of line relay L 102, Wire 25, polar contacts 26, 27, Wire 28, green light G and Wires v29, 29a, 29b and 7, to battery M B102. The open condition of polar contact 37 leaves the Hasher relayF 102 in its normally deenergized condi tionas shown.

Assuine that there is a train inwtrack section T 102,'track relay R 102 and-line relay L 102 will be (le-energized and its `front Contact 24 will be open and its back contact 18 will be closed. A following train in track section T 100 will energizey approach rlighting relay A 100 which willv closeits vfront contact 21 and close the red light circuit as follows: from battery M B 102, Wire 6, Wire 20, contact 21, wire 23,lbackc iitact 18, Wire 19, red light R and Wires 29, 29a,

29", 7 to battery M B 102.

In Fig.`2 the flashing operation is applied to the red light R. Otherwise the circuits are the saine as intFig. 1. The operation of the red light flashing circuit is as follows: Assume that there is a train in track sect-ion l 106. This, by actions AWhich will now be explained, Will give a flashing red light at signal 102 instead of a fiashing gifeen'light. A iillowiiigtiain in track section T 100 will energize approach lighting -relay A 100 and this by'closing its front contact 21 lcloses the operating circuit for polarized flasher relay i 'F 102 by a circuit which is the saine as has ybeen explained and thiswill. start the opera- Vtion of :the flasher Arelay F `102 `Which then voperates automatically as previously explained. Flasher lcontactffinger 31 now operates in unison With operating contact .45

and opensiandv closesthe flasher circuit-for .red Ilight R, the* circuit being as follows:

froin battery M B i102,.Wire 6, Wire I20,. contact 21 of approach lighting relay A 100,

vWire A22, Wire30,1flashcr Contact finger 31,`

Wire 32, contact v33, wire 34, polar contacts 35, Y36 .'(now closed) Wire 36a, Wire 19, red

M B 102. Bed light R now flasliesvtoggive .the caution indication. i

The ,red yflashing' light yniay be used for other pur-poses. 4At vaninterlocking plant it .inayibeused asfafcalling or signal toperniit a train to pass a stop signal. F or this purpose a speoialline control circuit Will be necy .essary 'lay 4L106 ai'e therefore energized, its pole .White light for proceeding.

VAt-'aii interlocking plant, other colorlight signalsk suchv as bluegaiid purpleinay'be operated .as flash light signals each for-giving tivo indications.V Onellasher relay at the tower inay befarranged to operate all flash iight signals in the interlocking' area.

rFig. 3 shows another forni of n'iy-inven' tion Whichprovides for alternate flashing of ;the redand green lights for givingthe caution indication. F or thispurpose, a neutral polar line relayis required. The operating circuit Yfor the flasher relay F 102 is-the saine as in-Figs. 1 and 2.

Theflashflight circuit for they green light .Gris'as follows z-fronrbattery M B 102,

Wire 6, Wire 20, contact 21 oi' approach lightfingrelay A100, Wire22, Wire 50, contact 51v of line relay L102, Wire 52,=neutral flasher contact 53 of iiasher relay'F 102, Wire 54, polar fiasherf contacts 5,5, 56, Wire 57, polar contact ,58 of line Arelay L 102, Wire 59, green lightG,.Wires 60,260, 60h, Wire-7 to battery M B 102. The fiash lightcircuit. forred light yR is as follows :-fro1n battery M B 102, Wire 6,fwirie 20, contact 21 of'appioach relay A 100, wire 22, Wire 50contact 51 of line relay L 102, Wire 52,-neuti'al flasher contact 53, Wire 5 4, polar.flashercontacts 55, 61, Wire 62, Wire 19 red light R, Wire60, 60a, 60 and avir-ef7 -to battery M B 102,

Neutral flasher contact 53 controls both the gieeirand the red light-circuits. Polar flasheijcontacts 55, 56 control the green light SG :and polar flasher contacts 55,61contiol the red light R. When flasher relay F 102 is in operation its polar flasher contacts 56 andy :61 are closed and opened alternately and thegrcen li glitGiand red light. R flash alter nat-ely. Y

m n ihe. operationoi-y the circuits inay noW be 'lightR and WireSaQQ, y29, 29, 7, to battery `i oo CTL - verse themagnetic condition of line relay L 102 at signal 102 and this reversal will throw its polar contact lingers 26 and 58 to the left. Everything is now in a position for giving the caution indication at signal 102. An east bound train in track section T 100 will energize approach lighting relay A V100 and close its front contact 21 which will Yclose the operating circuit for flasher relay F 102 which is the saine as previously explained. This Vputs neutral polar flasher relay F 102 inioperation the same as has been explained. Neutral flasher contact 53 now operates and closes and opens the flasher circuit for the red light R and the green light G as follows: from battery M B 102, wire 6, wire 20, contact 21, wire 22, wire 50, contact 51 of line relay L 102, wire 52, neutral flasher contact 53, wire 5l, polar flasher linger 55, contact 56, wire 57, polar contact finger 58 of line relay L 102 (now closed) contact 58a, wire 59, green light Gr, wires 60, 60a, 60b and wire `7 to battery M B 102. While polar flasher contact 56 is closed the Green lioht Gr isV aglow. Then polar contact 55 is thrown t0 the right the green light circuit will be open and the red light circuit will be closed as follows: from battery M B 102, wire 6, wire 20, contact 21 of approach lighting relay A 100, wire 22, wire 50, Contact 51 of line relay L 102, wire 52, neutral flasher contact 53, wire 5l, polar flasher contact finger 55, contact 61, wire 62, wire 19, red light R, wires 60, 60a, 60", wire 7 0 to battery M B102. lted light R will now beaglow instead of green light G. The green light and the red light therefore flash alternately and give the caution indication at signal 102.

The purpose of the neutral flasher contact 53 is to insure that the flasher light circuit will remain open when the flasher` relay F 102 is de-energized.

Alternately flashing thei green and red lights provides a very conspicuous aspect for giving the caution indication. Y

The flash light circuit arrangement as shown in Fig. 3 may be used as a substitute for either of the circuits shown in Figs. 1 and 2." By omitting the left hand polar contact 56, wire 57 and polar contact 58 of line relay L102 the red light only will flash. In a similar way by omitting the right hand pol a1' contact 61 and wire 62, the green light only will flash. i

I claim:

1. In a railway signal system, a stretch of A track divided into block sections, a two color light signahgoverning trallic in each section, a line relay, anflash'er device, a track relay,

and an approach lighting relay for each section, a circuitfor each line relay arranged gized anddeenergized condition ofthe cor-V responding line relay and also controlled by the approach lighting relay of a rear section, one ofthe light circuits being `also controlled jointly by its corresponding flasher opened or closed by its track l device and line relay, anda circuit for each flasher device controllerl-by the corresponding line relay, and the approach lighting relay of a rear track section.`` i

2. ln a railway signal system, a stretch of track divided into block sections, a two color light signalgoverning traffic in each section, a line relay,.a flasher device, a track` rela-y, and an approach lighting relay for each section, a circuit for each line relay arranged to he rev sed in direction of current flow upon energization and deenergization of anV advance line relay, means by whicheach line relay circuit is opened or closed'by its track relay, a light circuit for each color light of each signal closed alternately by the energized and deenergized condition of thecorre- `spending line relay and also controlled by the approach lighting relay of a rear section, one of the light circuits'being also controlled jofntly by its corresponding flasher device and line relay, and a circuit for each flasher device completed jointly by the reversal of polarity of its line relay and by an operation of the approach lighting relay of a rear track section when a train `enters that section.

3. ln a railway signal system, a stretch of track divided into block sections, a two color light signal governingtraliic in each section, a line relay, a flasher device, a track relay, and an approach lighting relay for each section, a circuit forl each linerelay arranged to be reversed in direction of current flow upon energiZat-ion and deenergization of anadvance line relay, means by which each line relay circuit is openedor closed by its track relay, a light circuit for each color light of each signal closed alternately by the energized and deenergized condition .of the corresponding line relay and also controlled by the approach lighting relay of a rear section, said 'light circuits lbeing Valso controlled jointly by the flasher device andl line relayV of that signal, said flasher device operating ing line relay andthe approach lighting relay of a rear track section. i j a. In a railway signal system, a stretch of` :track dividedinto block sections, a two color light signal governing traffic in each section, i

vpreaching the signal, and automatic aline relay7 a flasher device, a trackrelay, and an to be. reversed, circuitsfor the lights of each signal, the ciicuitofone of the lightsbeing completed by the linejrelay of that signalV whenc energized and theiothery beingy completed by the lino relay ofA that signal when deenei'gized, and means including an approach lightingy relay controlled byv` al track section rearwardly of each signal for noi'- mally interrupting. the lightcircuit of. thatV signal and effective upon the presence ofy a ti'ainY insaid rear section to closek for that signal the light Which is: completed by the line relay. y .y

5. In a railway signal systemaV stretch of trackdivided into block sectionsfaJ two-color` light signal: at theentrance toeach section and: governing trafficin that section, acircuitfor each colory lightofeach signahineans rendered active by a train `in L any section.- for closing, ay circuit .toi one light of. the: governmeans controlledv by a trackY section.- a'pproaching the signal for normally rinterrujnt-V ing the circuits of the signal lights-and clos-- ing. them When a: train is insaidisection apmea-ns for causing` a flashing of one of theV color lights cfa signal When trains are in sections at each side of the sect-ion With said flashing signal;

(5. In a railway signal system, a stretch of track divided into block sections, a tWo-color light signal at the entrance toveach section andi goverinngtrafhc in that section, a cir-l cuit for each color light of-eachsignalhmeans rendered active'by a trainfin any section for closing a ciicuit'to'onelight of the governing signal? of that' section' and interruptingsignal,l

the other color light of' the same means ycontrolled by a@ track section appreaching thek signal,` and automatic means for causing a flashing of the color. lights of a. signal alternately when trainsare inseetions at each side-ofV the sectionwith said flashing signal.

1f. In a railivay signal system, astretchof1 track divided into block sections, -.a light signal governing traffic in each section,l means rendered active by a train inI anyy section for' controlling the illumination of a light of the signal governing traffic in thatsection, and means controlled by the preceding means when operative to permit an illuminationof a signal light governing trafficin itssection for controlling a` flashing of a signal light at a signalr governing traffic in-a sectionl to therear ofI the section in vv-hich aftrain may be. l

approach lighting relay for eachy section, a circuitf'or each line relay arranged.

ing signal of: that section and: interruptingv the. other color lightl of the same sienah,

preaching the signal for normally interrupt-- ing the circuits ofthe sig-nal lightsrand closing them when a trainis-insaid sectionA ap# one ofv the lights designating 8; Inza railway signal system, a stretch of track divided into blocky sections, a multiliglit signal governing traffic in each section,

rone of the. lights designating danger and the. other proceed, means controlled by. a train in any section. for permitting a lighting offtliedanger light of' the'signal govern'- ingtraific in that section, means controlled by the preceding means when operative to pei-mit an illuminationof the danger signalr fori producing afflashing of a signal light .atl

a signal governing traffic in a section to they rear of the section in whicha train may be, to indicate caution, and means 4normally preventing illumination of all of said signals and rendered operative toV permit an illuminat-ionof one of' the lights of the signa-l for each section. as hereinbefore Vset forth by they p presence of a train ina track sectionto thek rear` of such. section.` l

9. In alrailvvay signal.system,y a stretch of-track divided into block sections,a multilight signal governing ltrafiic in each section, one ofthe lights 'effecting a lighting. ofV the danger light of the signal governing traffic in thatsection, and kmeans controlled by the preceding meansl for' producing a flashing-otra signal light at a track section in' the rear of said any section i for-indicating, the traffic condition in said any1 section l -l l.In a ,railwaysignalsystein,` a stretchy of` track divided into block sectionsa multilightsignal governing traffic in eachy section,

the other another traffic condition, means Vrenderedactive by a train in any section for effecting a lighting of the danger light of'y the signal governing traffic in that section, and means controlled by theprcceding means for producing an alternate flashing ofthe signallights at a. tracksection to the rear of said any section for` indicating: a traffic condition'in saidany section. i 12,-A In a railway signal system, a stretch of track-,divided into block-sections, 'a multiliglit-signal. governing: traffic in each section, one ofthe lightsl designating danger and? thel other another t-rafccondition, means designatingv dangery and the other proceed, means controlled by a designating danger and.

danger and i producing an alternate flashing of the signal A lightsat a track section to therear of said y 'orth by the light signal governing tion for proach lighting relay,

Vlighting relay being any` section for indicating a traflic condition in the last named section, and means normally preventing illumination of eachl sig-V nal and rendered operative to permit an illuinination as hereinbefore set forth by the presence ot' a train in a track section to the rear of said' signal.

`13; Ina railway signal system, o'f track divided into block sections, a multitraflic` in each sect-ion, means rendered active ,by a train in any section `liorellecting a lighting ot one light of the signal for that section and governing.

traflic approaching in the saine direction,

and means controlled by the preceding means, i and `effective when the latter is operative to 1 cause an illumination ot said one signalI light, for causing a. flashing ci' a signal light at a signal governingv trafiic in another section in the rear oisaid one signal' light,

14e. In a railway signal system, a stretch of track divided into block sections, a inulti` light signal governing traffic in each section, means rendered activeby a train in anysec effecting a lighting of one light off the signal for that section and governing traffic approaching in the saine direction, means controlled by the preceding means, and eflective when the latter is operative to cause an i illumination of said one signal light, for causing a flashing ota signal light at signal governing trafiic in another sec-` tion in the rear of said one signal light, and means normally preventing illumination ot' all of said signals andrendered operative to'v permit their illumination as presence of a train in atrack section to the rear 15. In a railway signal system, a stretch of track .divided into light signal governing traffic in each section, means rendered active vby a train in any section for effecting a lighting of one light of the signal for that section and governing traffic approaching in the same direction, and means controlled by the preceding means, Jtor causing a flashing of a light of another signal at a track section to the rear of said any section for indicating the trahie condition in said any section. y

16. In a railway signal system, a stretch of track divided into block sections,"a two color light signal governing trailic in each section, apolarized line relay, a track relay, an apand a flasher relay for each section, the track relay and approach directly controlled by their corresponding tracksection, each line light of a stretch hereinbefore set` y o 't each signal, afs-eachv signal is approached by the train.

block sections, al multirelay being controlled by its track relay and by thefpolar contacts of a line relay of an` other section in advance of the signal associated with said each line relay, a circuit Jfor the danger light of each signal completed vjointlybyone` condition of energization of theline relay for that signal and the' approach :lighting relay of atrack section in the rear of saidsignal, a, circuit for the other color light ofeach signal completed by another conditionof energization of said line relay and 'saidlapproachlighting relay, and ineans controlled jointly by each line relay when its polarity is reversed, the flasher relay otthat signal and the .approach lighting relay of a track section in the rear of said signal for causing a flashingof a color light ot asignal as a caution signal when trains arejinadjacentsectionsat tboth ends of the section controlled by said flashing color light.

1 17. In arailway signalqsysteln, alstretch of track divided intoblock sections, a two color light signal `governing traflic in each section, a polarized line relay, a track relay, an approach lighting relay, andi a flasher relay for each section, the track relay and ap roach lighting -relayibeing directly control ed by their corresponding track sectiomeachf line relay being controlled by itstrack relay and.

also as to polarityby the'line relay vof an other section in advance otits signal, a circuit lorthe dangerlight of each signal cornpleted jointly `by one condition of eneroiza tion ofthe line relay for that signal and the approach Alighting relay of a' track section in the rearfof said sional, a circuit for the other color light of eac signal completed by anotliercondition of energization ofsaid line` relayandthe approach lighting relay of said rear track section, `and means controlled jointly by each line relaywhen its polarity is reversed, he flasher relay of vthat, signal and theapproach lightingirelay of a track sectionitothe rear of said signal for causing an alternate flashing of the color` lights of a signal as i sections adjacent both ends of the section controlled by said flashing signal.`

. 18. In a railway signal system, a stretch of track divided into block sections, a two color light signal governing tralliciin each section, a polarized line relay, atrack relay, an approach lighting relay, larized flasher relay `for each section, the track relay and approach lighting relay being directly controlledby their correspondingtrack section, each line'relay being controlled by its track relay and by the polar contacts of a line relay of another section in advance of its signal, a circuit for the danger light ot each signal completed jointly by one condition of energization of the line relay for that signal and the approach lighting rea caution signal when trains are in and a self-acting po-V noY lili) signal completed by another condition of energization of said line relay andthe ap-k proach lighting relay of a track section in the rear of said signal, and means controlled jointly by each line relay when its polarity is reversed, the flasher relay of that signal and the approach lighting relay of a track section in t-he rear of said signal for causing a flashing of a color light of a signal as a caution signal when trains are in sections adjacent both ends of the section vcontrolled by said flashing color light.

19. In a railway signal system, a stretch of track divided into block sections, a two coloi light signal governing traffic in each section, a polarized line relay, a track relay and an approach lighting relay for each section, each line relay being controlled by its track relay, and by the polar contacts of a line relay of another section in advance of' itsv signal, a circuit for the danger light of each signal controlled jointly by one condition of energization of the line relay for that signal and tli-e approach lighting relay of a track section to the rear of said signal, a circuit for the other color light of each signal controlled jointly by another co-ndition of energizatioii of said line relay and the approach lighting relay of said rear track section, and

means controlled jointly by each line relay,

when its polarity is reversed, and the approach lighting relay of a track section to the rear of said signal for causing a flashing of a color light of a signal as a caution signal when trains are in sections adjacent bot-h ends of the section controlled by said flash` f ing color light. 1

20. In a railwayfsignal system, a stretch oftrack divided into block sections, a two color light signal governing traflic in each section, a polarized line relay, a track relay and an approach lighting relay for each sec# tion, each line relay being controlled by its track relay and by the polar' contacts of a line relay of another section in advance of its signal, a circuit for the danger light of each signal controlled jointly by onel condition of energization of the line relay for that signal and the approach lighting relay of a track section to the rear of said signal, a circuit for the other color light of each signal controlled jointly by another condition of energization of said line relay and the approach lighting relay ofk a `track section to the rear of said signal, and means controlled jointly by each line relay, when its polarity is reversed, and the approach lighting relay of a track section to the rear of said signal, causing an alternate flashing of the color lights of a signal as a caution signal when trains are in sections adjacent both ends of the section controlled by said flashing signal. f

2l. In a railwaylsignal system, a stretch contacts of a line relay of another section in advance of its signal, a circuit for one of the color lights of each signal controlled by one lcondition of energization of the line relay for' that signal, a circuit for the other color light of each signal controlled by another condition of energization of said line relay,

and means rendered active by each line relay when its polarity is reversed 'for causing a. flashing of a color vlight of its signal as the third signal effect of that signal.

22. In a'railway signal system, a stretch of track divided into block sections, a two color light signal governing traflic in each section, a polarized line relay, and a track relay for each section, each line relay being controlled b v its track relay and by the polar contacts of a line relay of another section in advance of signal, a circuit for one of the color lights of? each signal controlled by one condition of eneigization of the line relay for that signal, ay circuit. for theY other color light of each signal controlled by another condition of energization of said line relay, and means rendered active by eachline relay when its polarity is reversed for causing an alternate flashing of said color lights of' its signal as the third signal effect of that signal. Y

23. In a railway signal system, a stretch of track divided in to block sections, a lightV signal governing traffic in each section,

tion forcontrolling the lighting of alight of the signal governing trallic in that section and the flashing of a light of the signal governing traffic in a section in the rear of the train, and means for also controlling said signals permitting their display when trains approach said signals and preventing display at all other times. Y

A24. In a railwaysignal system, a stretch of trackclivided vinto block sections, a light signal governing traffic in each section, means rendered active by a train in any sec# tion for controlling the lighting of a light of the signal governing trailic in that section and the flashing of' a light of the signal governing trafiic in a section in the rear of the train, and means for also controlling said signals and rendered operative automatically.

ROBERT J. HEWETT.

ioo 

